The Boston Athenaeum has digitized its collection of Boston city directories. John Norman published the first such directory in 1789 under the formal title of The Boston Directory. Containing, A List of the Merchants, Mechanics, Traders, and others of the Town of Boston; in Order to enable Strangers to find the Residence of any Person. The 1789 Directory also included a map of Boston, lists of public offices, lawyers, medical professionals, bankers, and lists of the names and homes of engine-men (firefighters).
The Boston Directory appeared in 1789 and was published irregularly until 1825, when annual publication started.
You can read more at http://cdm.bostonathenaeum.org/cdm/landingpage/collection/p16057coll32.